End of sheet indicating device



July 29, 1958 A. E. PICARD END OF SHEET INDICATING DEVICE Filed se t. 14., 1955 INVENTOR. Jlfreoo fflll'fllc Pica/fa.

United States Patent END OF SHEET INDICATING DEVICE Alfredo Enrique Picard, Buenos Aires, Argentina Application September 14, 1955, Serial No. 534,216

8 Claims. (Cl. 197-189) This invention relates to an end of sheet indicating device which may be adapted to substantially any type of machine comprising sheet like material feeding means and more particularly this invention relates to an end of page indicating device which may be coupled to substantially any types of the known typewriters.

So far several suggestions have already been made for enabling the typist to ascertain beforehand and Without turning the roller platen, when the end of the page is about to reach the writing position.

One of the known embodiments of the end of page announcing devices consists of a graduated drum rigidly attached to one end portion of the roller platen and in functional relationship with an indicator or gage. Before using this device a blank page of the size and type of paper to be used for writing has to be passed through the typewriter to determine at what number of the graduation the page will end, and particular attention has to be paid with each new insertion that the same starting number of the drum is used.

This layout is of course a rather precarious solution and quite easily subject to errors.

An improvement over this known device in supplying the graduated drum with an adjustable indicator drum adjacent to the graduated drum, and its indicator may be placed adjacent any number of the drum thereby informing the typist constantly of the number which represents the end of the page.

The arrangement is however far from being perfect because obviously any type of page is usually larger than the periphery of the roller platen and therefore the mark of the indicator drum will appear to the typist eyes several times, that is to say once upon each complete rotation of the roller platen, and accordingly, the typist will still have to watch the size of the portion of the paper which has not yet been typed so as to know when the next appearance of the mark will really indicate the end of the page.

It is believed unnecessary to enter in further details concerning the above described known arrangements, and "as to the drawbacks thereof, since anybody skilled in the art can perfectly visualize them.

Bearing in mind all these drawbacks, an end of page indicating device for substantially any type of typewriter or any similar machine has been conceived, wherein said typewriter includes a roller platen and paper supporting means in the rear of said roller platen, said'end of page indicating device comprising an exploring member adapted to move relatively to'said paper supporting means and an end of page indicating means operable upon moveinent of said exploring member to release said end of page indicating means from a blank stop position.

This device although described and illustrated as applied to a typewriter may obviously be adapted to any type of machine comprising means for feeding sheet like material, 'such as calculating machines, textile machines and the like. The supporting plate of the typewriter may be replaced by any suitable plate connected to the machine over which the sheet like material passes, and consequently the scopeof this invention includesall such plates.

An object of this invention is to provide an end of page indicating device which is capable of amplifying a weak signal by means of the energy obtained from the rotation of the roller platen.

Another object of the invention is to provide a device that cannot be disturbed by vibrations or any abnormal position the typewriter may adopt since the device does not operate by gravity.

Another object of this invention is to provide an end of page indicating device which gives clear and exact indie'ation's, which cannot be misunderstood, without having to set any indicator or the like, nor to remember any data, when the end of the page is approaching.

Another object of the invention is to provide a device capable of indicating not only the approaching of the end of the page but also the exact amount of remaining available space or lines of the paper by direct reading.

A further object of the invention is to provide a device that can be adapted to almost any typewriter without introducing substantial modifications.

A still further object of the invention is to provide a device which can be used with any type of and size of paper even if the size is constantly changed and without requiring any particular adjustment for such change.

Further objects and advantages of the present invention Will become apparent during the course of the following description in which two preferred embodiments are described by way of example.

In the drawings:

Fig. 1 is a partial perspective view of a typewriter including an end of page indicating device according to the invention. 1

Fig. 2 is a detail in perspective view, on an enlarged scale, showing the end portion of the exploring arm and related parts.

Fig. 3 is a detail in longitudinal section of part of the clutching means.

Fig. 4 is an end view of the end of page indicating device of the present invention, including means for automatically raising the exploring arm.

Fig. 5 is a detail in perspective view, on an enlarged scale, showing a modified construction of the end portion of the exploring arm.

As shown in Fig. 1, the end of page indicating device -is mounted on a common type of typewriter including a rotatable roller platen 1, manually operable by means of r a knob'z, through a roller shaft 3, or by means of a line feeding lever (not shown) arranged at the opposite end 'of roller 1. Paper supporting means consisting of an inclined guiding plate 4 is located in the rear of said roller platen 1, for guiding and supporting the portion of the paper not yet typed on, while roller platen 1 feeds said paper in front of the writing means of the typewriter.

A pair of cylindrical friction rings 5 and 6 '(see Fig. 3) are rigidly mounted, in spaced relationship, on said shaft 3. An indicating drum 7 having on its periphery a .iplurality of graduations 8 isloosely mounted onsaid 'shaft 3 and adapted to frictionally contact with said friction ring 5. The roller platen 1 will rotate upon operation of the feeding lever (not shown) in one unit hereinafter called a line. The magnitude of the arc defining the line may be varied according to the circumstances.

Aprojecting rim '10 is integral with one end portion of indicating drum 7, that corresponding to the outer fa'ce9 of indicating drum 7. Said rim 16} has a slot 11, the purpose-of which will be later explained.

An exploring member, consisting of a three-armed lever 12, -is loosely mounted on said shaft 3 and its supporting arm 27 is in frictional contact with the inner face of friction ring 6. A roller 13 is rotatably mounted on the free end portion of exploring arm 28 forming part of said lever 12, said roller 13 facing a slot 14 in the guiding plate 4, and being capable of entering said slot 14, upon rotation of said three-armed lever.

The downwardly projecting arm 15 of lever 12 is adapted to engage the rear end of a locking lever 16, pivotally supported by a pivot 29 mounted on the typewriter carriage 33. Said locking lever 16 has a locking tooth 17 facing the indicating drum rim 10 and is adapted to engage and disengage slot 11, as will be later seen. A tension spring 19 is connected to said lever 16 between said pivot 29 and said tooth 17 and said spring is further linked to the carriage 33. The front end portion of locking lever 16 rests, in the engaged position, on a stop 18 mounted on the typewriter carriage 33, due tothe spring action, as seen in Figure l.

Indicating drum 7 (see Fig. 3) and the supporting arm 27 of lever 12 are pressed against the respective friction rings 5 and 6 by means of a compression spring 20 coiled on said shaft 3 and located between the outer face 9 of drum 7 and said supporting arm 27.

As the pressure exerted by spring 20 produces a friction between the contacting surfaces of friction ring 5 and drum 7, and between friction ring 6 and supporting arm 27, the rotation of roller platen 1 is thus transmitted both to said indicating drum 7 and said lever 12 through arm 27, when the tooth 17 is disengaged from slot 11, as will be later seen.

There is a plate 21 having a window 21' facing the graduated periphery of indicating drum 7 and being visible from the typists position. A gage or arrow 22 may be marked on plate 21 in order to define the exact position of the successive graduations appearing in said window 21'. Said plate 21 is mounted on the ruler 30 (as shown) or on any other suitable part.

The graduations on the periphery of the indicating drum 7 are numbered preferably from zero (0) to ten (10) and these have between the first and last number a blank space. Slot 11 faces locking tooth 17 when said blank space faces said indicating window 21'.

The operation of the device of the present invention will be described, assuming that the typewriter is empty, that is to say without paper and that the position of the indicating drum 7 is that obtained from a previous use of the machine. The indicating window 21' shows generally the number zero (0), since this is the position which identifies the end of the paper. However any other initial position of the indicating drum 7 will not modify the correct operation of the device.

Before inserting paper, roller platen 1 is rotated backwards about two lines, lever 12 being thus lifted due to its frictional engagement with friction ring 6, leaving thereby clearance for the insertion of paper between roller 13 and guiding plate 4. The counterclockwise movement of lever 12 (seen from knob 2) may be limited by a stop (not shown) mounted on the carriage 33, the rear portion of locking lever 16 being then out of contact with arm 15, whereby spring 19 tends to lower locking tooth 17. This movement will be performed as soon as tooth 17 faces slot 11, but meanwhile said tooth 17 rests on indicating drum rim 10.

Paper is now inserted in the normal way, introducing its leading edge in the slot formed by the roller platen 1 and guiding plate 4 passing it beneath lifted lever 12. The page, if required, may be aligned in the normal way by depressing the auxiliary clamping roller control lever (not shown) which will not affect in any way the operation of the device of the present invention.

Paper is advanced to the position where typing will begin by actuating roller control knob 2. The rotation of roller platen 1 in clockwise direction will now rotate lever 12, in a clockwise direction, the roller 13 of which will meet the inserted paper sheet, which at this time covers slot 14 of the guiding plate 4, the said roller exerting a very slight pressure on the paper. In this position the downwardly projecting arm 15 of lever 12 will not contact the rear end of locking lever 16, and the latter will thus elastically maintain its locking tooth 17 on the rim 10. When said slot 11 faces said locking tooth 17, the latter will engage the former preventing drum 7 from further rotation together with roller platen 1, which is possible due to the elastic engagement of spring 20.

The indicating window 21' will now show the blank space and the device is ready to indicate when the end portion of the paper approaches the typing position. When the paper has reached a position about 11 lines from its bottom edge the guiding plate slot 14 will be cleared by the bottom edge of the paper thus allowing the clockwise rotation of lever 12, the roller 13 of which will now enter slot 14. As a result, arm 15 of lever 12 will contact and downwardly push the rear end of locking lever 16, disengaging slot 11 of indicating drum 7.

- Further rotation of roller platen 1 will drive indicating drum 7 due to its frictional engagement, and arrow 22 will identify the successive numerical graduations 8 appearing in window 21. These numbers announce the number of lines which are not yet typed in addition to the line that has been advanced at that moment.

It will be understood that further unit rotations of roller platen 1 will bring subsequent decreasing numbers under window 21' and finally, when the number zero appears, the last useable line has been reached and the following operation of the line feeding lever (not shown) will force the sheets out of the sheet clamping arrangement of the typewriter and the position of the device will be that assumed at the beginning of the description.

If the remaining space is not an exact number of lines, the indicating arrow 22 will indicate a point between two numbers and will be accordingly displaced towards the one, indicating the closer line.

When an erasure or any other correction is to be made on the type part of the sheet, it is necessary to advance the paper some lines in order to bring the portion to be corrected to the top of the roller platen 1, and once this operation has been performed, the page must be returned to its original position in order to proceed with the typing. If these movements of roller platen 1 do not cause the bottom end of the page to pass over the guiding plate slot 14, the device will not modify its operative position, since the indicating drum 7 is retained by locking tooth 17. However if the forward and backward movements of the feeding roller 1 cause the end of the page to pass over the slot 14 of the guiding plate thus disengaging the indicating drum 7, any difliculty is prevented because any counterclockwise rotation of the roller platen 1 lifts arm 12 thus leaving clearance for the return movement of the paper.

In order to end suddenly the contact between the paper and roller 13, that otherwise would decrease gradually due to the roundness of the latter, when the end of the paper passes over slot 14, arm 28 of lever 12 is provided with a projection 23 (see Fig. 2) of smaller height than the radius of the roller 13, which maintains the lever 12 in the raised position until the slot 14 is completely cleared.

Projection 23 may be formed, as shown in Fig. 5, by a free end bent portion integral with exploring arm 28, rotatably supporting roller 13.

The device may be provided with additional means for automatically lifting lever 12, whereby the device would not require any attention nor any additional manipulation of roller platen 1, while inserting the paper.

As shown in Fig. 4 said additional means comprises a cam 24, rigidly attached to the outer face 9 of drum 7 and a lifting arm 25, pivoted at its rear end on a pivot 31 supported by the typewriter carriage, and controlled by cam 24 through cam follower 26, rotatably mounted in the middle portion of arm 25. The front end of lifting arm 25 is linked by means of link 27' to lever 12.

The fiat portion 32:0f. cam 24 is located substantially op,- posite slot 11=andis definedbya small chord.

As will beunderstood whenever. drumv 7 isretained by locking tooth 17, lever 12 is contacting the-.paper; when the end of the. page has arrived, and drum 7 is consequently freed, the. rotation of the. latter will bring the portion of greatestradiusof cam24into engagement withroller 26 causing theliftingof lever 12..

Although theclutching frictions produced by. spring 20, between the contacting faces .of. drum 7 and lever 12 andv their respective friction; rings arepractically equal, the frictional engagementtbetween drum:7 and. friction ring 5, will prevail becausezthe lifting action. oflever 12 is transmitted by a greater sector of cam.24..

The device may also be provided with an audible alarm which may be operated forinstanceby indicating drum 7.

It is obvious thatothen modifications may be. introduced, such as placing the arrangement on the other side of .the carriage, and it is notsconsidered necessary tode? scribe furtherdetails of thesepossible. changes.

From the foregoing it; will. now be. obvious. thatthe device described and illustratedas. appliedv to, a typea writer may be. appliedtoany type of machine which is provided with means. for feeding...lamin arstock, such. as calculating machines, textile machines, etc,

I claim:

1. In a typewriter having a carriage, a roller platen mounted on saidcarriage and havingarollerplaten shaft, a. keyboard in. front ofsaid roller. platen, and paper supporting. means in the. rear. ofsaid rollerplaten, an end of page announcing devicecomprising a first.friction means rigidly mounted on.said.roller platenshaft, a secand. friction..means spacedapart from. said. first friction ring andalso mounted. onsaidrollerplaten. shaft, an.in-. dicatingv drum having, a. graduated] periphery loosely mounted. on said. shaft between, saidfirst and Isecond. fric: tion means and. adjacent .said first friction means, .an. exploring member loosely mountedon said. roller platen shaft between said first and said second friction means and adjacent said second friction means, an elastic member in abutting contact with.said indicating. drum. and said. exploring member, said. papersupportingmeans have inga first slot, said exploringmember having; a freeend portion adaptedto enter said first slot, and a locking lever pivotally supportedon said. .carriage, saidjindicating drum having a second slot capable of facing. said. locking lever, said locking lever-.being. capable ofentering saidv second slot thereby locking said indicating drum,.said locking lever having an end portion, said endportion facing. said exploring member which is capable of engaging and. driving said locking lever thereby removing. saidlocking lever from said second slot.

2. In a typewriter having a. carriage, arollerplaten mounted on said carriage and having a roller platen shaft, a keyboard. in frontofsaid roller;v platen, and. paper supporting means inthe rearof said roller. platen, an. end of page announcing device comprising a. first. friction means rigidly mounted on said roller platen shaft, a second friction means spaced apart from-said first friction ring and also rigidly mounted. on. said roller platenshaft, an indicatingdrurn having a graduate-dfperiphery loosely mounted on said shaft between said. first and. second friction means and adjacent said'first friction means, an exploring membe-r loosely mounted on said roller platen shaft between said first and'said second friction means and adjacent said second friction means, an elastic member in abutting contact with, said indicatingv drum and said exploring member, said paper supportingmeans having a first slot, saidexploring member having a free end portion, .adap.ted.to.enter said..firstaslot,-' a lockinglever pivotally supported on said carriage, said indicating drum having a second slot capable of facing said locking lever, said locking lever being capable of entering said second slot thereby locking said indicating drum, said locking lever having an end portion, said end portion facing said exploring member which is capable of engaging and. driving said locking lever therebyremoving said locking lever from said second slot, and automatic meansv for raising said. exploring member upon disengagingv said locking lever from said second slot.

3. In a typewriter having a carriage, a roller platen mounted on said carriage and having a roller platen shaft, 'a. keyboard in front of saidiroller platen, and paper sup.- porting means in the rear of said roller platen, an end of page announcing device. comprising afirst friction means rigidly mounted on said roller platen shaft, a second frietionmeans spaced apart from said first frictionring and also. rigidly mounted on said roller platent shaft, an indicating drum having a graduated periphery loosely mounted on said shaft between said first and. second friction means and adjacent said first friction ring, an

, exploring .member consisting ,of a vthreearm lever. having a. supporting arm, an exploring arm and a downwardly projecting arm, said supporting arm being loosely mounted on said roller platen shaftbetween said first and said second. friction means and adjacent said second-friction means, an elastic member in abutting contact with said indicating. drum and said exploringv member, said paper supporting means having a first slot, said exploring memberhaving a free endportion, adapted to enter said first slot, a locking lever pivotally supported on said carriage, said indicating drum having a second slot capable of facing said locking lever, said locking tooth being capable of entering said second slot thereby locking said indicating drum, said locking lever-:having an. endportion, said end portion facing said exploring memberwhich is capable of engaging and..driving said locking-lever thereby removing said locking lever from said second'slot, and automatic means for raising said exploring member upon disengag ing. said locking leverv from said'second. slot,,said auto: maticmeans comprising a. cam rigidly attached. to said indicating drum, a lifting lever having one end and being pivotally supported on said carriage, said end being linked to said exploring member, and a cam follower rotatably mounted on said lifting lever and in contact with said cam, said cam having a portionof smaller. radius than the rest of the cam, substantially opposite saidsecond slot.

4. In a typewriter having a carriage, a roller platen mounted on said carriage and having a roller platen shaft, a keyboard in front of said roller platen, and paper sup; porting means in the rear of said roller platen, an end of page. announcing device comprising a first frictionmeans rigidly mounted on said roller platen shaft, a second friction means spaced apart from said first frictionring and also rigidly mounted on said roller platen shaft, anindicating drum having a graduated periphery loosely mounted on said shaft between said first and second friction means and adjacent said first friction means, .an exploringmerm ber loosely mounted on said roller platenv shaft between saidfirst and said second friction means and adjacent said second friction means, an elastic member in abutting contact with said indicating drum and said exploring member, said paper supporting means having a first :slot, said exploring member having a free end portion, a roller loosely mounted on said freeend portionv and facing sm'd first slot and adapted to enter said first slot, and a locking lever pivotally supported on said carriage, .said indicating drum having a second slot capable of facing said lock-I ing lever, said locking lever being capable. of entering said second slot thereby lockingsaid indicating drum, said locking lever having an end portion, said. end portion facingsaid exploring member which is capable of ena gaging and driving said lockinglever thereby. removing said locking lever from said second slot. i

5. In a typewriter having a carriage, a roller platen mounted on said carriage and having a roller platen shaft, a keyboard in front of said roller platen, and paper supporting means in the rear of said roller platen, an end of page announcing device comprising a first friction ring rigidly mounted on said roller platen shaft, a second friction ring spaced apart from said first friction ring and also rigidly mounted on said roller platen shaft, an indicating drum having a graduated periphery loosely mounted on said shaft between said first and second friction rings and adjacent said first friction ring, an exploring member loosely mounted on said roller platen shaft between said first and said second friction ring and adjacent said second friction ring, an elastic member mounted on said roller platen shaft and in abutting contact with said indicating drum and said exploring member, said paper supporting means having a first slot, said exploring member having a free end portion, a roller loosely mounted on said free end portion and facing said first slot and adapted to enter said first slot, and a locking lever having a locking tooth and pivotally supported on said carriage, said indicating drum having a second slot capable of facing said locking tooth, said locking tooth being capable of entering said second slot thereby locking said indicating drum, said locking lever having an end portion, said end portion facing said exploring member which is capable of engaging and driving said locking lever thereby removing said locking tooth from said second slot.

6. In a typewriter having a carriage, a roller platen mounted on said carriage and having a roller platen shaft, a keyboard in front of said roller platen, and paper supporting means in the rear of said roller platen, an end of page announcing device comprising a first friction ring rigidly mounted on said roller platen shaft, a second friction ring spaced apart from said first friction ring and also rigidly mounted on said roller platen shaft, an indicating drum having a graduated periphery loosely mounted on said shaft between said first and second friction rings and adjacent said first friction ring, an exploring member consisting of a three arm lever having a supporting arm, an exploring arm and a downwardly projecting arm, said supporting arm being loosely mounted on said roller platen shaft between said first and said second friction ring and adjacent said second friction ring, a helical compression spring coiled on said roller platen shaft and in abutting contact with said indicating drum and said supporting arm, said exploring arm being substantially parallelly arranged to said paper supporting.

means, said paper supporting means having a first slot, said exploring arm having a free end portion, a roller loosely mounted on said free end portion and facing said first slot and adapted to enter said first slot, and a locking lever having a locking tooth and pivotally supported on said carriage, said indicating drum having a second slot capable of facing said locking tooth, said locking tooth being capable of entering said second slot thereby locking said indicating drum, said locking lever having a rear end portion, said rear end portion facing said downwardly projecting arm and said downwardly projecting arm being capable of engaging and driving said locking lever thereby removing said locking tooth from said second slot.

7. In a typewriter having a carriage, a roller platen mounted on said carriage and having a roller platen shaft, a keyboard in front of said roller platen, and paper supporting means in the rear of said roller platen, an end of page announcing device comprising a first friction ring rigidly mounted on said roller platen shaft, a second friction ring spaced apart from said first friction ring and also rigidly mounted on said roller platen shaft, an indicating drum having a graduated periphery loosely mounted on said shaft between said first and second friction ring and adjacent said first friction ring, an exploring member consisting of a three arm lever having a supporting arm, an exploring arm and a downwardly projecting arm, said supporting arm being loosely mounted on said roller platen shaft between said first and said second friction ring and adjacent said second friction ring, a helical compression spring coiled on said roller platen shaft and in abutting contact with said indicating drum and said supporting arm, said exploring arm being substantially parallelly arranged to said paper supporting means, said paper supporting means having a first slot, said exploring arm having a free end portion, a roller loosely mounted on said free end portion and facing said first slot and adapted to enter said first slot, a locking lever having a locking tooth and pivotally supported on said carriage, said indicating drum having a second slot capable of facing said locking tooth, said locking tooth being capable of entering said second slot thereby locking said indicating drum, said locking lever having a rear end portion, said rear end portion facing said downwardly projecting arm and said downwardly projecting arm being capable of engaging and driving said locking lever thereby removing said locking tooth from said second slot, and a plate rigidly mounted on said carriage and having a window facing said indicating drum and located between said keyboard and said roller platen, said graduated periphery including a blank space capable of facing said window when said locking tooth is located in said second slot.

8. In a typewriter having a carriage, a roller platen mounted on said carriage and having a roller platen shaft, a keyboard in front of said roller platen, and paper supporting means in the rear of said roller platen, an end of page announcing device comprising'a first friction ring rigidly mounted on said roller platen shaft, a second friction ring spaced apart from said first friction ring and also rigidly mounted on said roller platen shaft, an indicating drum having a graduated periphery loosely mounted on said shaft between said first and second friction rings and frictionally coupled to said first friction ring, an explor ing member consisting of a three arm lever having a supporting arm, an exploring arm having a free end and a downwardly projecting arm, said supporting arm being loosely mounted on said roller platen shaft between said first and said second friction ring and frictionally coupled to said second friction ring, a helical compression spring coiled on said roller platen shaft and in abutting contact with said indicating drum and said supporting arm, said exploring arm being substantially parallelly arranged to said paper supporting means, said paper supporting means having a first slot, said exploring arm having a free end portion, a roller loosely mounted on said free end portion and facing said first slot and adapted to enter said first slot, a locking lever having a locking tooth and pivotally supported on said carriage, said indicating drum having a second slot capable of facing said locking tooth, said locking tooth being capable of entering said second slot thereby locking said indicating drum, said locking lever having a rear end portion, said rear end portion facing said downwardly projecting arm and said downwardly projecting arm being capable of engaging and driving said locking lever thereby removing said locking tooth from said second slot, a plate rigidly mounted on said carriage and having a window facing said indicating drum periphery and located between said keyboard and said roller platen, said graduated periphery including a blank space capable of facing said window when said locking tooth is located in said second slot, and a projection mounted on the free end of said exploring arm of smaller height than the radius of said roller and likewise facing said first slot and capable of entering the latter.

References Cited in the file of this patent UNITED STATES PATENTS 1,114,633 Neidig Oct. 20, 1914 

